Power supply apparatus

ABSTRACT

Disclosed is a power supply apparatus. The power supply apparatus includes a first magnetic core; a second magnetic core having a shape equal to a shape of the first magnetic core; a third magnetic core between the first and second magnetic cores; a first coil wound around one of the first and third magnetic cores; and a second coil wound around one of the second and third magnetic cores.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims priority under 35 U.S.C. 119 and 35U.S.C. 365 to Korean Patent Application No. 10-2011-0077639 (filed on 4Aug. 2011), which is hereby incorporated by reference in its entirety.

BACKGROUND

Recently, electronic products have various functions and superiorperfolinance and have tended toward the small-size and light-weight. Inorder to realize the electronic products having the small-size andlight-weight, the size or volume of parts installed in the electronicproducts must be reduced.

In particular, as the semiconductor integrated circuits have beendeveloped, circuits can be prepared with the small-size and lightweight. However, there is a problem to reduce the volume of an inductorinstalled in the electronic products. In this regard, studies andresearch have been continuously performed to reduce the size and theweight of the inductor installed in the electronic product.

Meanwhile, a PFC (Power Factor Correction) converter, which is an inputpower factor correction circuit, has been extensively used for a powersupply apparatus of the electronic product in response to the demand forreducing harmonics and correcting input power factor in commercialpower.

In addition, in order to reduce the ripple of input current Iin and toimprove the efficiency of the PFC converter, an interleaved PFCconverter (or interleaved boost converter) employing two individualinductors has been used.

To this end, according to the related art, an air gap is essentiallyrequired in an intermediate magnetic path or a lateral magnetic path ofa core to manufacture a couple inductor. However, in order to form theair gap, an additional cutting work is necessary, so the manufacturingcost may be increased and the management for the air gap may bedifficult.

SUMMARY

The embodiment provides a power supply apparatus including an inductor,a transformer and an inductor-transformer having the novel structure.

Technical objects of the embodiment may not be limited to the aboveobject and other technical objects of the embodiment will be apparent tothose skilled in the art from the following description.

A power supply apparatus according to the embodiment includes a firstmagnetic core; a second magnetic core having a shape equal to a shape ofthe first magnetic core; a third magnetic core between the first andsecond magnetic cores; a first coil wound around one of the first andthird magnetic cores; and a second coil wound around one of the secondand third magnetic cores.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1 a and 1 b are circuit views showing a power supply apparatusincluding a couple inductor according to the embodiment;

FIGS. 2 a to 18 are views showing a couple inductor according to theembodiment;

FIG. 19 is a view showing a power supply apparatus including a coupletransformer according to the embodiment;

FIGS. 20 to 23 are views showing a couple transformer according to theembodiment;

FIG. 24 is a view showing a power supply apparatus including a coupleinductor-transformer according to the embodiment;

FIGS. 25 to 29 are views showing a power supply apparatus including acouple inductor-transformer according to the embodiment;

FIG. 30 is a view showing a couple inductor, a couple transformer and acouple inductor-transformer according to another embodiment; and

FIG. 31 is view showing an experimental result obtained by a coupleinductor manufactured according to the embodiment.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Hereinafter, the embodiments will be described with reference toaccompanying drawings in detail so that those skilled in the art towhich the invention pertains can easily realize the embodiments.However, the embodiments may have various modifications withoutlimitation.

In the following description, when a part is referred to as it includesa component, the part may not exclude other components but furtherinclude another component unless the context indicates otherwise.

The thickness and size of each layer shown in the drawings may beexaggerated, omitted or schematically drawn for the purpose ofconvenience or clarity. In addition, the size of elements does notutterly reflect an actual size. In the following description, thesimilar components will be assigned with the similar reference numeralsthroughout the specification.

FIGS. 1 a and 1 b are circuit views showing a power supply apparatusincluding a couple inductor according to the embodiment;

As shown in FIG. 1 a, the power supply apparatus 100 including theinductor may include a filter 110, a rectifying unit 120 and a powerfactor correction unit 130.

The filter 110 is provided at an input side to which commercial power(85V to 260V) is input in order to reduce conductive noise.

To this end, the filter 110 may include coils provided at a pair ofpower lines, respectively, and a capacitor connected to the power linesin parallel at both ends of the coils. The coils may be common modechock coils and two windings are provided per one core at in-phase.

The rectifying unit 120 is connected to an output side of the filter 110to rectify the wave of the commercial power. The rectifying unit 120 isa bridge diode BD including a plurality of diodes.

The power factor correction unit 130 charges/discharges the energyaccumulated in inductors L1 and L2 through the operation ofsemiconductor switches S1 and S2 to make input voltage and currentin-phase.

The power factor correction unit 130 includes a first inductor L1, asecond inductor L2, a first semiconductor switch Si for switching thecharge/discharge operation of the first inductor L1, a secondsemiconductor switch S2 for switching the charge/discharge operation ofthe second inductor L2, a first diode D1 connected to the first inductorL1, a second diode D2 connected to the second inductor L2 and an outputcondenser Co. Reference numeral R_(L) represents resistance.

Meanwhile, the power supply apparatus according to the embodiment isapplicable not only for AC input power as shown in FIG. 1 a, but alsofor DC input power as shown in FIG. 1 b.

FIG. 1 b is a view showing a power supply apparatus 100′ according toanother embodiment. The power supply apparatus 100′ may be a DC/DCconverter.

The power supply apparatus 100′ shown in FIG. 1 b includes the powerfactor correction unit having the structure the same as that of thepower factor correction unit 130 included in the power supply apparatus100 shown in FIG. 1 a, so the detailed description thereof will beomitted.

Hereinafter, the structure of the couple inductor including the firstand second inductors L1 and L2 will be described.

The couple inductor according to the embodiment may include a corehaving the shape of U, |, U or |, H, |. Although an air gap can beseparately prepared, a gap sheet or a core having low permeability(powder core) is employed to form the air gap, instead of cutting amagnetic path to form the air gap, thereby reducing the cost requiredfor the cutting process.

In addition, the above structure of the couple inductor can be used forthe structure of a couple transformer and the structure of a coupleinductor-transformer in which the inductor is integrated with thetransformer.

FIG. 2 a is a view showing a couple inductor according to the firstembodiment.

Referring to FIG. 2 a, the couple inductor 200 includes a first magneticcore 210, a second magnetic core 220, a third magnetic core 230, a firstcoil 240 wound around the first magnetic core 210, and a second coil 250wound around the second magnetic core 220.

The first magnetic core 210 has a shape of ‘U’.

In addition, the second magnetic core 220 also has a shape of ‘U’. Inthis case, the first magnetic core 210 is arranged in the shape of ‘U’and the second magnetic core 220 is arranged symmetrically to the firstmagnetic core 210 while interposing the third magnetic core 230therebetween.

In detail, the first magnetic core 210 includes a first core part 211having a shape of ‘|’, a second core part 212 extending from one end ofthe first core part 211 (an upper end of the first core part in thedrawing) vertically to the length direction of the first core part 211,and a third core part 213 extending from the other end of the first corepart 211 (a lower end of the first core part in the drawing) verticallyto the length direction of the first core part 211.

Similarly, the second magnetic core 220 includes a first core part 221having a shape of ‘|’, a second core part 222 extending from one end ofthe first core part 221 (an upper end of the first core part in thedrawing) vertically to the length direction of the first core part 221,and a third core part 223 extending from the other end of the first corepart 221 (a lower end of the first core part in the drawing) verticallyto the length direction of the first core part 221.

The third magnetic core 220 has a shape of ‘|’ and is interposed betweenthe first and second magnetic cores 210 and 220.

In addition, the couple inductor 200 according to the first embodimentincludes the first coil 240 wound around the first magnetic core 210 andthe second coil 250 wound around the second magnetic core 220.

In detail, the first coil 240 is wound around the first core part 211 ofthe first magnetic core 210. At this time, the first coil 240 is woundaround the center portion of the first core part 211 of the firstmagnetic core 210 several times.

In addition, the second coil 250 is wound around the first core part 221of the second magnetic core 220. At this time, the second coil 250 iswound around the center portion of the first core part 221 of the secondmagnetic core 220 several times.

Meanwhile, the first coil 240 can be wound lengthwise along the firstmagnetic core 210. Preferably, as shown in FIG. 2 a, the first coil 240can be wound lengthwise along the first core part 211 of the firstmagnetic core 210.

In the same manner, the second coil 250 can be wound lengthwise alongthe second magnetic core 220. Preferably, as shown in FIG. 2 a, thesecond coil 250 can be wound lengthwise along the first core part 221 ofthe second magnetic core 220.

At this time, a first air gap (Ig) 260 is formed between the first andthird magnetic cores 210 and 230 and a second air gap (Ig) 270 is formedbetween the second and third magnetic cores 220 and 230.

A top surface of the second core part 212 of the first magnetic core 210is aligned on the same plane with a top surface of the third magneticcore 230. In addition, a bottom surface of the third core part 213 ofthe first magnetic core 210 is aligned on the same plane with a bottomsurface of the third magnetic core 230.

As a result, the first air gap 260 is formed between the right lateralside of the second core part 212 of the first magnetic core 210 and theleft lateral side of the third magnetic core 230. In addition, the firstair gap 260 is formed between the right lateral side of the third corepart 213 of the first magnetic core 210 and the left lateral side of thethird magnetic core 230. According to the first embodiment, the firstair gap 260 may be formed between right lateral sides of the second andthird core parts 212 and 213 of the first magnetic core 210 and the leftlateral side of the third magnetic core 230, respectively.

In the same manner, a top surface of the second core part 222 of thesecond magnetic core 220 is aligned on the same plane with a top surfaceof the third magnetic core 230. In addition, a bottom surface of thethird core part 223 of the second magnetic core 220 is aligned on thesame plane with a bottom surface of the third magnetic core 230.

As a result, the second air gap 270 is formed between the left lateralside of the second core part 222 of the second magnetic core 220 and theright lateral side of the third magnetic core 230. In addition, thesecond air gap 270 is formed between the left lateral side of the thirdcore part 223 of the second magnetic core 220 and the right lateral sideof the third magnetic core 230. According to the first embodiment, thesecond air gap 270 may be formed between left lateral sides of thesecond and third core parts 222 and 223 of the second magnetic core 220and the right lateral side of the third magnetic core 230, respectively.

In detail, according to the first embodiment, the couple inductor 200including two inductors is prepared as an integrated couple inductor bywinding coils around the core. Although it is possible to form the airgap through the conventional cutting process, according to theembodiment, the air gap is simply formed by employing a gap sheet or abottom without performing the cutting process when manufacturing thecouple inductor.

Meanwhile, as shown in FIG. 2 b, the winding scheme for the first andsecond coils 240 and 250 of the couple inductor 200 may be differentfrom the winding scheme shown in FIG. 2 a.

That is, as shown in FIG. 2 b, the first coil 240 may be wound aroundthe first magnetic core 210 in the direction crossing the lengthdirection of the first magnetic core 210, which is different from FIG. 2a. Preferably, as shown in FIG. 2 b, the first coil 240 can be woundaround the first core part 211 of the first magnetic core 210 in thedirection crossing the length direction of the first core part 211 ofthe first magnetic core 210.

In the same manner, the second coil 250 may be wound around the secondmagnetic core 220 in the direction crossing the length direction of thesecond magnetic core 220. Preferably, as shown in FIG. 2 b, the secondcoil 250 can be wound around the first core part 221 of the secondmagnetic core 220 in the direction crossing the length direction of thefirst core part 221 of the second magnetic core 220.

Meanwhile, as shown in FIG. 2 c, the first coil 240 of the coupleinductor 200 may include a primary coil 240 a wound around the firstcore part 211 of the first magnetic core 210 and a secondary coil 240 bwound around the third magnetic core 230 while being connected to theprimary coil 240 a in series.

In addition, the second coil 250 of the couple inductor 200 may includea tertiary coil 250 a wound around the first core part 221 of the secondmagnetic core 220 and a quaternary coil 250 b wound around the thirdmagnetic core 230 while being connected to the tertiary coil 250 a inseries.

FIG. 3 a is a view showing a couple inductor according to the secondembodiment.

Referring to FIG. 3 a, the couple inductor 300 includes a first magneticcore 310, a second magnetic core 320, a third magnetic core 330, a firstcoil 340 wound around the first magnetic core 310, and a second coil 350wound around the second magnetic core 320.

The first magnetic core 310 has a shape of ‘U’.

In addition, the second magnetic core 320 also has a shape of ‘U’. Inthis case, the first magnetic core 310 is arranged in the shape of ‘U’and the second magnetic core 320 is arranged symmetrically to the firstmagnetic core 310 while interposing the third magnetic core 330therebetween.

In detail, the first magnetic core 310 includes a first core part 311having a shape of ‘|’, a second core part 312 extending from one end ofthe first core part 311 (an upper end of the first core part in thedrawing) vertically to the length direction of the first core part 311,and a third core part 313 extending from the other end of the first corepart 311 (a lower end of the first core part in the drawing) verticallyto the length direction of the first core part 311.

Similarly, the second magnetic core 320 includes a first core part 321having a shape of ‘|’, a second core part 322 extending from one end ofthe first core part 321 (an upper end of the first core part in thedrawing) vertically to the length direction of the first core part 321,and a third core part 323 extending from the other end of the first corepart 321 (a lower end of the first core part in the drawing) verticallyto the length direction of the first core part 321.

The third magnetic core 320 has a shape of ‘|’ and is interposed betweenthe first and second magnetic cores 310 and 320.

In addition, the couple inductor 300 according to the second embodimentincludes the first coil 340 wound around the first magnetic core 310 andthe second coil 350 wound around the second magnetic core 320.

In detail, the first coil 340 is wound around the second core part 312of the first magnetic core 310. At this time, the first coil 340 iswound around the center portion of the second core part 312 of the firstmagnetic core 310 several times.

In addition, the second coil 350 is wound around the second core part322 of the second magnetic core 320. At this time, the second coil 350is wound around the center portion of the second core part 322 of thesecond magnetic core 320 several times.

At this time, a first air gap (Ig) 360 is formed between the first andthird magnetic cores 310 and 330 and a second air gap (Ig) 370 is formedbetween the second and third magnetic cores 320 and 330.

That is, according to the first embodiment, the coils 240 and 250 arewound around the first core parts 211 and 221 of the first and secondmagnetic cores 210 and 220, and, according to the second embodiment, thecoils 340 and 350 are wound around the second core parts 312 and 322 ofthe first and second magnetic cores 310 and 320.

Meanwhile, as shown in FIG. 3 b, the first coil 340 of the coupleinductor 300 may include a primary coil 340 a wound around the secondcore part 312 of the first magnetic core 310 and a secondary coil 340 bwound around a third core part 313 of the first magnetic core 310 whilebeing connected to the primary coil 340 a in series.

In addition, the second coil 350 of the couple inductor 300 may includea tertiary coil 350 a wound around the second core part 332 of thesecond magnetic core 320 and a quaternary coil 350 b wound around athird core part 323 of the second magnetic core 320 while beingconnected to the tertiary coil 350 a in series.

FIG. 4 is a view showing a couple inductor according to the thirdembodiment.

Referring to FIG. 4, the couple inductor 300 according to the thirdembodiment includes a first magnetic core 410, a second magnetic core420, a third magnetic core 430, a first air gap 460 and a second air gap470, which have the structure the same as that of the first embodiment.

According to the couple inductor 200 of the first embodiment, the coilsare wound around the first core parts of the first and second magneticcores, and, according to the second embodiment, the coils are woundaround the second core parts of the first and second magnetic cores.

However, according to the third embodiment, a first coil 440 is woundaround a third core part 413 of the first magnetic core 410 and a secondcoil 450 is wound around a third core part 423 of the second magneticcore 420.

At this time, the first magnetic cores 210, 310 and 410, the secondmagnetic cores 220, 320 and 420, and the third magnetic cores 230, 330and 430 according to the first to third embodiments may include ferritecores having the magnetic property of high permeability.

FIG. 5 is a view showing a couple inductor according to the fourthembodiment.

Referring to FIG. 5, the couple inductor 500 includes a first magneticcore 510 having a shape of ‘U’, a second magnetic core 520 having ashape the same as that of the first magnetic core 510 and disposedsymmetrically to the first magnetic core 510, and a third magnetic core530 having a shape of ‘|’ and disposed between the first and secondmagnetic cores 510 and 520.

In addition, the couple inductor 500 includes a first coil 540 woundaround the first magnetic core 510 and a second coil 550 wound aroundthe second magnetic core 520.

Although it is illustrated that the first coil 540 is wound around thesecond core part of the first magnetic core 510 and the second coil 550is wound around the second core part of the second coil 550, this isillustrative purpose only. For instance, as illustrated in the first andthird embodiments, the first and second coils 540 and 550 can be woundaround the first core parts or the third core parts of the first andsecond magnetic cores, respectively.

According to the fourth embodiment, different from the first to thirdembodiments, the air gap may not be formed between the first and thirdmagnetic cores 510 and 530 and between the second and third cores 520and 530.

To this end, according to the fourth embodiment, the first and secondmagnetic cores 510 and 520 are formed by using the same material and thethird magnetic core 530 is formed by using the material different fromthe material for the first and second magnetic cores 510 and 520.

That is, the first and second magnetic cores 510 and 520 may includepowder cores having low permeability and the third magnetic core 530 mayinclude a ferrite core having high permeability.

In other words, the air gap is not formed in the couple inductor and themagnetic cores are prepared by using different magnetic materials, sothe eddy current losses generated from the first and second coils 540and 550 caused by the fringing flux can be reduced. In addition, sincethe couple inductor is fabricated without the air gap, the additionalprocess, such as the cutting process, may be omitted.

FIG. 6 is a view showing a couple inductor according to the fifthembodiment.

Referring to FIG. 6, the couple inductor 600 includes a first magneticcore 610, a second magnetic core 620, a third magnetic core 630, a firstcoil 640 and a second coil 650, which have the shapes identical to thoseof the couple inductor 500 according to the fourth embodiment.

Although the first and second magnetic cores 510 and 520 according tothe fourth embodiment have the magnetic property of low permeability,the first and second magnetic cores 610 and 620 according to the fifthembodiment have the magnetic property of high permeability.

Therefore, contrary to the fourth embodiment, the third magnetic core630 has the magnetic property of low permeability different from thefirst and second magnetic cores 610 and 620.

FIG. 7 is a view showing a couple inductor according to the sixthembodiment.

Referring to FIG. 7, the couple inductor 700 includes a first magneticcore 710, a second magnetic core 720, a third magnetic core 730, a firstcoil 740 and a second coil 750, which have the shapes identical to thoseof the couple inductor 300 according to the second embodiment.

According to the second embodiment, a plurality of first air gaps 360are formed between the first and third magnetic cores 310 and 330 and aplurality of second air gaps 370 are formed between the second and thirdmagnetic cores 320 and 330 due to the structures of the first to thirdmagnetic cores 310, 320 and 330.

However, according to the sixth embodiment, one third air gap 760 isformed between the first and third magnetic cores 710 and 730 and onefourth air gap 770 is formed between the second and third magnetic cores720 and 730.

To this end, one end of a third core part 713 of the first magnetic core710 is cut such that the first magnetic core 710 can be spaced apartfrom the third magnetic core 730, thereby forming the third air gap 760.In addition, one end of a third core part 723 of the second magneticcore 720 is cut such that the second magnetic core 720 can be spacedapart from the third magnetic core 730.

At this time, since only one air gap is formed between the first andthird magnetic cores 710 and 730 of the couple inductor 700 and only oneair gap is formed between the second and third magnetic cores 720 and730 of the couple inductor 700, the width of the third and fourth airgaps 760 and 770 is wider than the width of the first and second airgaps 360 and 370.

Thus, in the couple inductor 700, a second core part 712 of the firstmagnetic core 710 is longer than the third core part 713 and a secondcore part 722 of the second magnetic core 720 is longer than the thirdcore part 723 of the second magnetic core 720.

In addition, the first coil 740 may be wound around the first core part711 of the first magnetic core 710 and the second coil 750 may be woundaround the first core part 721 of the second magnetic core 720.

FIG. 8 is a view showing a couple inductor according to the seventhembodiment.

Referring to FIG. 8, the couple inductor 800 includes a first magneticcore 810, a second magnetic core 820, a third magnetic core 830, a firstcoil 840 and a second coil 850, which have the shapes identical to thoseof the couple inductor 700 according to the sixth embodiment.

According to the couple inductor 700 of the sixth embodiment, the fourthair gap 770 is formed between the third core part 723 of the secondmagnetic core 720 and the third magnetic core 730. However, according tothe couple inductor 800 of the seventh embodiment, a fourth air gap 870is formed between a second core part 822 of the second magnetic core 820and the third magnetic core.

In other words, according to the couple inductor 700 of the sixthembodiment, the third and fourth air gaps 760 and 770 are formed at thebottom surface of the couple inductor 700 together. However, accordingto the couple inductor 800 of the seventh embodiment, third and fourthair gaps 860 and 870 are separately formed at the top and bottomsurfaces of the couple inductor 800, respectively.

Thus, a third core part 823 of the second magnetic core 820 is longerthan a second core part 822 of the second magnetic core 820 in thecouple inductor 800 according to the seventh embodiment.

FIG. 9 a is a view showing a couple inductor according to the eighthembodiment.

Referring to FIG. 9 a, the couple inductor 900 includes a first magneticcore 910, a second magnetic core 920, a third magnetic core 930, a firstcoil 940, a second coil 950, a fifth air gap 960 and a sixth air gap970.

The first and second magnetic cores 910 and 920 may have the same shapeof ‘|’.

The third magnetic core 930 is formed between the first and secondmagnetic cores 910 and 920. The third magnetic core 930 has a shape of‘H’, which is different from the shape of the first and second magneticcores 910 and 920.

In detail, the third magnetic core 930 includes a fourth core part 931having a shape of ‘|’, a fifth core part 932 vertically extending fromone end of the fourth core part 931 (an upper end of the fourth corepart in the drawing) in the left direction with respect to the lengthdirection of the fourth core part 931, a sixth core part 933 verticallyextending from one end of the fourth core part 931 in the rightdirection, a seventh core part 934 vertically extending from the otherend of the fourth core part 931 (a lower end of the fourth core part inthe drawing) in the left direction, and an eighth core part 935vertically extending from one end of the fourth core part 931 in theright direction.

At this time, the first and second magnetic cores 910 and 920 areparallel to a fourth core part 931 of the third magnetic core 930.

In addition, the first and second magnetic cores 910 and 920 are longerthan the fourth core part 931 of the third magnetic core 930.

Thus, the right side of the first magnetic core 910 may face the fifthcore part 932 and the left side of the seventh core part 934 of thethird magnetic core 930. In addition, the left side of the secondmagnetic core 920 may face the sixth core part 933 and the right side ofthe eighth core part 935 of the third magnetic core 930.

Therefore, the fifth air gap 960 may be formed among the right side ofthe first magnetic core 910, the fifth core part 932 and the left sideof the seventh core part 934 of the third magnetic core 930. Inaddition, sixth air gap 970 may be formed among the left side of thesecond magnetic core 920, the sixth core part 933 and the right side ofthe eighth core part 935 of the third magnetic core 930.

The first coil 940 is wound around the first magnetic core 910 and thesecond coil 950 is wound around the second magnetic core 920.

At this time, the first coil 940 may be wound lengthwise along the firstmagnetic core 910. In addition, the second coil 950 may be woundlengthwise along the second magnetic core 920.

Meanwhile, as shown in FIG. 9 b, the first coil 940 may be wound aroundthe first magnetic core 910 in the direction crossing the lengthdirection of the first magnetic core 910. In the same manner, the secondcoil 950 can be wound around the second magnetic core 920 in thedirection crossing the length direction of the second magnetic core 920.

Further, as shown in FIG. 9 c, the first coil 940 may include a primarycoil 940 a wound around the first magnetic core 910 and a secondary coil940 b wound around the fourth core part 931 of the third magnetic core230 while being connected to the primary coil 940 a in series.

In addition, the second coil 950 may include a tertiary coil 950 a woundaround the second magnetic core 920 and a quaternary coil 950 b woundaround the third magnetic core 230 while being connected to the tertiarycoil 950 a in series.

FIG. 10 a is a view showing a couple inductor according to the ninthembodiment.

Referring to FIG. 10 a, the couple inductor 1000 includes a firstmagnetic core 1010, a second magnetic core 1020, a third magnetic core1030, a fifth air gap 1060 and a sixth air gap 1070, which are similarto those of the couple inductor 900 according to the eighth embodiment.

According to the eighth embodiment, the first coil 940 is wound aroundthe first magnetic core 910 and the second coil 950 is wound around thesecond magnetic core 920. However, according to the ninth embodiment,first and second coils 1040 and 1050 are wound around the third magneticcore 1030.

In detail, the first coil 1040 is wound around a fifth coil part 1032 ofthe third magnetic core 1030 and the second coil 1050 is wound around asixth coil part 1033 of the third magnetic core 1030.

Meanwhile, as shown in FIG. 10 b, the first coil 1040 may include aprimary coil 1040 a wound around a fifth core part 1032 of the thirdmagnetic core 1030 and a secondary coil 1040 b wound around a seventhcore part 1034 of the third magnetic core 1030 while being connected tothe primary coil 1040 a in series.

In addition, the second coil 1050 may include a tertiary coil 1050 awound around a sixth coil part 1033 of the third magnetic core 1030 anda quaternary coil 1050 b wound around an eighth core part 1035 of thethird magnetic core 230 while being connected to the tertiary coil 1050a in series.

FIG. 11 is a view showing a couple inductor according to the tenthembodiment.

Referring to FIG. 11, the couple inductor 1100 includes a first magneticcore 1110, a second magnetic core 1120, a third magnetic core 1130, afifth air gap 1160 and a sixth air gap 1170, which are similar to thoseof the couple inductors 900 and 1000 according to the eighth and ninthembodiments.

According to the eighth embodiment, the first coil 940 is wound aroundthe first magnetic core 910 and the second coil 950 is wound around thesecond magnetic core 920. However, according to the tenth embodiment,first and second coils 1140 and 1150 are wound around the third magneticcore 1130.

In detail, the first coil 1140 is wound around a seventh coil part 1134of the third magnetic core 1130 and the second coil 1150 is wound aroundan eighth coil part 1135 of the third magnetic core 1130.

FIG. 12 is a view showing a couple inductor 1200 according to theeleventh embodiment.

Referring to FIG. 12, the couple inductor 1200 includes a first magneticcore 1210, a second magnetic core 1220, a third magnetic core 1230, afirst coil 1240 and a second coil 1250, which are similar to those ofthe couple inductor 900 according to the eighth embodiment.

The fifth and sixth air gaps 960 and 970 are included in the eighthembodiment, but the couple inductor 1200 according to the eleventhembodiment may not include an air gap.

Thus, the first magnetic core 1210 makes contact with the third magneticcore 1230 and the second magnetic core 1220 makes contact with the thirdmagnetic core 1230.

In addition, the first and second cores 1210 and 1220 are formed byusing the same magnetic material and the third magnetic core 1230 isformed by using the magnetic material different from the magneticmaterial for the first and second magnetic cores 1210 and 1220.

That is, the first and second magnetic cores 1210 and 1220 may includepowder cores having low permeability and the third magnetic core 1230may include a ferrite core having high permeability.

In other words, the air gap is not formed in the couple inductor and themagnetic cores are prepared by using different magnetic materials, sothe eddy current losses generated from the first and second coils 1240and 1250 caused by the fringing flux can be reduced. In addition, sincethe couple inductor is fabricated without the air gap, the additionalprocess, such as the cutting process, may be omitted.

FIG. 13 is a view showing a couple inductor according to the twelfthembodiment.

Referring to FIG. 13, the couple inductor 1300 includes a first magneticcore 1310, a second magnetic core 1320, a third magnetic core 1330, afirst coil 1340 and a second coil 1350, which have the shapes identicalto those of the couple inductor 1200 according to the eleventhembodiment.

Although the first and second magnetic cores 1210 and 1220 according tothe eleventh embodiment have the magnetic property of low permeability,the first and second magnetic cores 1310 and 1320 according to thetwelfth embodiment have the magnetic property of high permeability.

Therefore, contrary to the eleventh embodiment, the third magnetic core1330 has the magnetic property of low permeability different from thefirst and second magnetic cores 1310 and 1320.

FIG. 14 is a view showing a couple inductor according to the thirteenthembodiment.

Referring to FIG. 14, the couple inductor 1400 includes a first magneticcore 1410, a second magnetic core 1420, a third magnetic core 1430, afirst coil 1440 and a second coil 1450, which have the shapes identicalto those of the couple inductor 900 according to the eighth embodiment.

According to the eighth embodiment, a plurality of fifth air gaps 960are formed between the first and third magnetic cores 910 and 930 and aplurality of sixth air gaps 970 are formed between the second and thirdmagnetic cores 920 and 930 due to the structures of the first to thirdmagnetic cores 910, 920 and 930.

However, according to the thirteenth embodiment, one fifth air gap 1460is formed between the first and third magnetic cores 1410 and 1430 andone sixth air gap 1470 is formed between the second and third magneticcores 1420 and 1430.

To this end, one end of a fifth core part 1432 of the third magneticcore 1430 is cut such that the third magnetic core 1430 can be spacedapart from the first magnetic core 1410, thereby forming the fifth airgap 1460. In addition, one end of a sixth core part 1433 of the thirdmagnetic core 1430 is cut such that the third magnetic core 1430 can bespaced apart from the second magnetic core 1420, thereby forming thesixth air gap 1470.

At this time, since only one air gap is formed between the first andthird magnetic cores 1410 and 1430 of the couple inductor 1400 and onlyone air gap is formed between the second and third magnetic cores 1420and 1430 of the couple inductor 1400, the width of the fifth and sixthair gaps 1460 and 1470 is wider than the width of the fifth and sixthair gaps 960 and 970 according to the eighth embodiment.

Thus, in the couple inductor 1400, a fifth core part 1432 of the thirdmagnetic core 1430 is longer than a fifth core part 1434 and an eighthcore part 1435 of the third magnetic core 1430 is longer than a sixthcore part 1433.

In addition, the first coil 1440 may be wound around the first magneticcore 1410 and the second coil 1450 may be wound around the secondmagnetic core 1420.

FIG. 15 is a view showing a couple inductor according to the fourteenthembodiment.

Referring to FIG. 15, the couple inductor 1500 includes a first magneticcore 1510, a second magnetic core 1520, a third magnetic core 1530, afirst coil 1540 and a second coil 1550, which have the shapes identicalto those of the couple inductor 1400 according to the thirteenthembodiment.

According to the couple inductor 1400 of the thirteenth embodiment, thesixth air gap 1470 is formed between the sixth core part 1433 of thethird magnetic core 1430 and the second magnetic core 1420. However,according to the couple inductor 1500 of the fourteenth embodiment, asixth air gap 1570 is formed between an eighth core part 1535 of thethird magnetic core 1530 and the second magnetic core.

In other words, according to the couple inductor 1400 of the thirteenthembodiment, the fifth and sixth air gaps 1460 and 1470 are formed at thetop surface of the couple inductor 1400 together. However, according tothe couple inductor 1500 of the fourteenth embodiment, fifth and sixthair gaps 1560 and 1570 are separately formed at the top and bottomsurfaces of the couple inductor 1500, respectively.

Thus, a sixth core part 1533 of the third magnetic core 1530 is longerthan an eighth core part 1535 of the third magnetic core 1530 in thecouple inductor 1500 according to the fourteenth embodiment.

FIG. 16 is a view showing a couple inductor according to the fifteenthembodiment.

Referring to FIG. 16, the couple inductor 1600 includes a first magneticcore 1610, a second magnetic core 2620, a third magnetic core 2630, afirst coil 1640, a second coil 1650, a fifth air gap 1660 and a sixthair gap 1670, which are similar to those of the couple inductor 900according to the eighth embodiment.

The first and second magnetic cores 1610 and 1620 may have the sameshape of ‘|’.

The third magnetic core 1630 is formed between the first and secondmagnetic cores 1610 and 1620. The third magnetic core 1630 has a shapeof ‘H’, which is different from the shape of the first and secondmagnetic cores 1610 and 1620.

According to the fifteenth embodiment, different from the eighthembodiment, the first and second magnetic cores 1610 and 1620 may havethe length the same as that of a fourth core part 1631 of the thirdmagnetic core 1630.

Thus, the top surface of the first magnetic core 1610 faces the bottomsurface of a fifth core part 1632 of the third magnetic core 1630, andthe bottom surface of the first magnetic core 1610 faces the top surfaceof a seventh core part 1634 of the third magnetic core 1630. Inaddition, the top surface of the second magnetic core 1620 faces thebottom surface of a sixth core part 1633 of the third magnetic core1630, and the bottom surface of the second magnetic core 1620 faces thetop surface of an eighth core part 1635 of the third magnetic core 1630.

As a result, one fifth air gap 1660 is formed between the top surface ofthe first magnetic core 1610 and the bottom surface of the fifth corepart 1632 of the third magnetic core 1630, and another fifth air gap1660 is formed between the bottom surface of the first magnetic core1610 and the top surface of the seventh core part 1634 of the thirdmagnetic core 1630. In addition, one sixth air gap 1670 is formedbetween the top surface of the second magnetic core 1620 and the bottomsurface of the sixth core part 1633 of the third magnetic core 1630, andanother sixth air gap 1670 is formed between the bottom surface of thesecond magnetic core 1620 and the top surface of the eighth core part1635 of the third magnetic core 1630.

The first coil 1640 is wound around the first magnetic core 1610 and thesecond coil 1650 is wound around the second magnetic core 1620.

FIG. 17 is a view showing a couple inductor according to the sixteenthembodiment.

Referring to FIG. 17, the couple inductor 1700 includes a first magneticcore 1710, a second magnetic core 1720, a third magnetic core 1730, afifth air gap 1760 and a sixth air gap 1770, which are similar to thoseof the couple inductor 1600 according to the fifteenth embodiment.

First and second coils 1740 and 1750 are wound around the third magneticcore 1730.

In detail, the first coil 1740 is wound around a fifth core part 1732 ofthe third magnetic core 1730 and the second coil 1750 is wound around asixth core part 1733 of the third magnetic core 1730.

FIG. 18 is a view showing a couple inductor according to the seventeenthembodiment.

Referring to FIG. 18, the couple inductor 1800 includes a first magneticcore 1810, a second magnetic core 1820, a third magnetic core 1830, afifth air gap 1860 and a sixth air gap 1870, which are similar to thoseof the couple inductor 1600 according to the fifteenth embodiment.

At this time, the first coil 1840 is wound around a seventh core part1834 of the third magnetic core 1830 and the second coil 1850 is woundaround an eighth core part 1835 of the third magnetic core 1830.

FIG. 19 is a view showing a power supply apparatus according to theembodiment.

Referring to FIG. 19, the power supply apparatus 1900 includes a firsttransformer and a second transformer.

The first transformer includes a primary coil part 1910 and a secondarycoil part 1920. In addition, the second transformer also includes aprimary coil part 1930 and a secondary coil part 1940. In this case, theprimary coil parts 1910 and 1930 may include a plurality of coils.

Hereinafter, the structure of a couple transformer including the firstand second transformers will be described.

The structure of the couple transformer may be identical to thestructure of the couple inductor described above. However, although thefirst and second coils are wound in the couple inductor, a plurality ofprimary coils and one secondary coil are wound instead of the first coiland a plurality of primary coils and one secondary coil are woundinstead of the second coil in the couple transformer.

Therefore, the structure of the couple transformer according to oneexemplary embodiment from among various embodiments will be describedbelow and the structure of the couple inductor, which may be omitted inthe description for the structure of the couple transformer, will beapplicable for the structure of the couple transformer.

FIG. 20 a is a view showing a couple transformer according to the firstembodiment.

Referring to FIG. 20 a, the couple transformer 2000 includes a firstmagnetic core 2010, a second magnetic core 2020, a third magnetic core2030, a first air gap 2060, and a second air gap 2070, which areidentical to those of the couple inductor 200 shown in FIG. 2.

However, although the inductor coils 240 and 250 are wound around thefirst and second magnetic cores 210 and 220 in the couple inductor 200,transformer coils 2040 and 2050 are wound around the first and secondmagnetic cores 2010 and 2020 in the couple transformer 2000.

In detail, the first transformer coil 2040 including primary andsecondary coils 2041 and 2042 is wound around the first magnetic core2010, and the second transformer coil 2050 including primary andsecondary coils 2051 and 2052 is wound around the second magnetic core2020.

At this time, the first transformer coil 2040 can be wound lengthwisealong the first magnetic core 2010. In the same manner, the secondtransformer coil 2050 can be wound lengthwise along the second magneticcore 2020.

Meanwhile as shown in FIG. 20 b, the first transformer coil 2040 may bewound around the first magnetic core 2010 in the direction crossing thelength direction of the first magnetic core 2010. In the same manner,the second transformer coil 2050 may be wound around the second magneticcore 2020 in the direction crossing the length direction of the secondmagnetic core 2020.

FIG. 21 a is a view showing a couple transformer according to the secondembodiment.

Referring to FIG. 21 a, the couple transformer 2100 includes a firstmagnetic core 2110, a second magnetic core 2120, a third magnetic core2130, a first air gap 2160, and a second air gap 2170, which areidentical to those of the couple transformer 2000 shown in FIG. 20 a.

A first transformer coil 2140 is wound around a second core part 2112located at an upper portion of the first magnetic core 2110, and asecond transformer coil 2150 is wound around a second core part 2122located at an upper portion of the second magnetic core 2120.

Meanwhile, as shown in FIG. 21 b, the first transformer coil 2140 mayinclude a primary transformer coil 2140 a wound around the second corepart 2112 of the first magnetic core 2110 and a secondary transformercoil 2140 b wound around a third core part 2113 of the first magneticcore 2110 and connected to the primary transformer coil 2140 a inseries.

In the same manner, the second transformer coil 2150 may include atertiary transformer coil 2150 a wound around the second core part 2122of the second magnetic core 2120 and a quaternary transformer coil 2150b wound around a third core part 2123 of the second magnetic core 2120and connected to the tertiary transformer coil 2150 a in series.

FIG. 22 a is a view showing a couple transformer according to the thirdembodiment.

Referring to FIG. 22 a, the couple transformer 2200 includes a firstmagnetic core 2210, a second magnetic core 2220, a third magnetic core2230, a fifth air gap 2260, and a sixth air gap 2270, which areidentical to those of the couple inductor 900 shown in FIG. 9 a.

However, although the inductor coils 940 and 950 are wound around thefirst and second magnetic cores 910 and 920 in the couple inductor 900,transformer coils 2240 and 2250 are wound around the first and secondmagnetic cores 2210 and 2220 in the couple transformer 2200.

In detail, the first transformer coil 2240 including primary andsecondary coils 2241 and 2242 is wound around the first magnetic core2210, and the second transformer coil 2250 including primary andsecondary coils 2251 and 2252 is wound around the second magnetic core2220.

At this time, the first transformer coil 2240 can be wound lengthwisealong the first magnetic core 2210. In the same manner, the secondtransformer coil 2250 can be wound lengthwise along the second magneticcore 2220.

Meanwhile as shown in FIG. 22 b, the first transformer coil 2240 may bewound around the first magnetic core 2210 in the direction crossing thelength direction of the first magnetic core 2210. In the same manner,the second transformer coil 2250 may be wound around the second magneticcore 2220 in the direction crossing the length direction of the secondmagnetic core 2220.

FIG. 23 a is a view showing a couple transformer according to the fourthembodiment.

Referring to FIG. 23 a, the couple transformer 2300 includes a firstmagnetic core 2310, a second magnetic core 2320, a third magnetic core2330, a fifth air gap 2360, and a sixth air gap 2370, which areidentical to those of the couple transformer 2200 according to the thirdembodiment.

Different from the third embodiment in which the first and secondtransformer coils 2240 and 2250 are wound around the first and secondmagnetic cores 2210 and 2220, respectively, the first and secondtransformer coils 2340 and 2350 are wound around the third magnetic core2330 in the fourth embodiment.

In detail, the first transformer coil 2340 is wound around a fifth corepart 2332 located at an upper left portion of the third magnetic core2330 and the second transformer coil 2350 is wound around a sixth corepart 2333 located at an upper right portion of the third magnetic core2330.

Meanwhile, as shown in FIG. 23 b, the first transformer coil 2340 mayinclude a primary transformer coil 2340 a wound around the fifth corepart 2332 of the third magnetic core 2330 and a secondary transformercoil 2340 b wound around a seventh core part 2334 of the third magneticcore 2330 and connected to the primary transformer coil 2340 a inseries.

In the same manner, the second transformer coil 2350 may include atertiary transformer coil 2350 a wound around the sixth core part 2333of the third magnetic core 2330 and a quaternary transformer coil 2350 bwound around an eighth core part 2335 of the third magnetic core 2330and connected to the tertiary transformer coil 2350 a in series.

FIG. 24 is a view showing a power supply apparatus according to theembodiment.

Referring to FIG. 24, the power supply apparatus 2400 includes aninductor 2410 and a transformer 2420. The transformer 2420 includesprimary and secondary coils.

Hereinafter, the structure of a couple inductor-transformer includingthe inductor 2410 and the transformer 2420 will be described.

The structure of the couple inductor-transformer may be identical to thestructure of the couple inductor described above. However, although thefirst and second coils are wound in the couple inductor, a transformercoil including a plurality of primary coils and one secondary coil iswound instead of the second coil in the couple inductor-transformer.

In the following description, the structure and elements that have beendescribed with reference to the couple inductor will be omitted in orderto avoid redundancy.

Therefore, the structure of the couple inductor-transformer according toone exemplary embodiment from among various embodiments will bedescribed below and the structure of the couple inductor, which may beomitted in the description for the structure of the coupleinductor-transformer, will be applicable for the structure of the coupleinductor-transformer.

FIG. 25 a is a view showing a couple inductor-transformer according tothe first embodiment.

Referring to FIG. 25 a, the couple inductor-transformer 2500 includes afirst magnetic core 2510, a second magnetic core 2520, a third magneticcore 2530, a first air gap 2560, and a second air gap 2570, which areidentical to those of the couple inductor 200 shown in FIG. 2.

However, although the inductor coils 240 and 250 are wound around thefirst and second magnetic cores 210 and 220 in the couple inductor 200,a transformer coil 2550 is wound around the second magnetic core 2520 inthe couple inductor-transformer 2500.

In detail, an inductor coil 2540 is wound around the first magnetic core2510 and a transformer coil 2550 including primary and secondary coils2551 and 2552 is wound around the second magnetic core 2520.

At this time, the inductor coil 2540 can be wound lengthwise along thefirst magnetic core 2510. In the same manner, the transformer coil 2550can be wound lengthwise along the second magnetic core 2520.

Meanwhile as shown in FIG. 25 b, the inductor coil 2540 may be woundaround the first magnetic core 2510 in the direction crossing the lengthdirection of the first magnetic core 2510. In the same manner, thetransformer coil 2550 may be wound around the second magnetic core 2520in the direction crossing the length direction of the second magneticcore 2520.

FIG. 26 is a view showing a couple inductor-transformer according to thesecond embodiment.

Referring to FIG. 26, the couple inductor-transformer 2600 includes afirst magnetic core 2610, a second magnetic core 2620, a third magneticcore 2630, a first air gap 2660, and a second air gap 2670, which areidentical to those of the couple inductor-transformer 2500 shown in FIG.25.

An inductor coil 2640 is wound around a third core part 2613 located ata lower portion of the first magnetic core 2610, and a transformer coil2650 is wound around a third core part 2633 located at a lower portionof the second magnetic core 2620.

FIG. 27 a is a view showing a couple inductor-transformer according tothe third embodiment.

Referring to FIG. 27 a, the couple inductor-transformer 2700 includes afirst magnetic core 2710, a second magnetic core 2720, a third magneticcore 2730, a first air gap 2760, and a second air gap 2770, which areidentical to those of the couple transformer 900 shown in FIG. 9 a.

However, although the inductor coils 940 and 950 are wound around thefirst and second magnetic cores 910 and 920 in the couple inductor 900,an inductor coil 2740 is wound around the first magnetic core 2710 and atransformer coil 2750 is wound around the second magnetic core 2720 inthe couple inductor-transformer 2700.

At this time, the inductor coil 2740 can be wound lengthwise along thefirst magnetic core 2710. In the same manner, the transformer coil 2750can be wound lengthwise along the second magnetic core 2720.

Meanwhile as shown in FIG. 27 b, the inductor coil 2740 may be woundaround the first magnetic core 2710 in the direction crossing the lengthdirection of the first magnetic core 2710. In the same manner, thetransformer coil 2750 may be wound around the second magnetic core 2720in the direction crossing the length direction of the second magneticcore 2720.

FIG. 28 is a view showing a couple inductor-transformer according to thefourth embodiment.

Referring to FIG. 28, the couple inductor-transformer 2800 includes afirst magnetic core 2810, a second magnetic core 2820, a third magneticcore 2830, a fifth air gap 2860, and a sixth air gap 2870, which areidentical to those of the couple inductor-transformer 2700 according tothe third embodiment.

However, although the inductor coil 2740 and the transformer coil 2750are wound around the first and second magnetic cores 2710 and 2720 inthe third embodiment, an inductor coil 2840 and a transformer coil 2850are wound around the third magnetic core 2830 in the fourth embodiment.

In detail, the inductor coil 2840 is wound around a fifth core part 2832located at an upper left portion of the third magnetic core 2830 and thetransformer coil 2850 is wound around a sixth core part 2833 located atan upper right portion of the third magnetic core 2830.

FIG. 29 is a view showing a couple inductor-transformer according to thefifth embodiment.

Referring to FIG. 29, the couple inductor-transformer 2900 includes afirst magnetic core 2910, a second magnetic core 2920, a third magneticcore 2930, a fifth air gap 2960, and a sixth air gap 2970, which areidentical to those of the couple inductor-transformer 2800 according tothe fourth embodiment.

However, an inductor coil 2940 is wound around a seventh core part 2934located at a lower left portion of the third magnetic core 2730, and atransformer coil 2950 is wound around an eighth core part 2935 locatedat a lower right portion of the third magnetic core 2930.

FIG. 30 is a view showing a couple inductor, a couple transformer and acouple inductor-transformer according to another embodiment.

Referring to FIG. 30, each of the couple inductor, the coupletransformer and the couple inductor-transformer may include a firstmagnetic core 3010, a second magnetic core 3020, a third magnetic core3030, a fourth magnetic core 3040, a fifth magnetic core 3050, a firstcoil 3060 wound around the first magnetic core 3010, a second coil 3070wound around the second magnetic core 3020, a third coil 3080 woundaround the third magnetic coil 3030, and a fourth coil 3090 wound aroundthe fourth magnetic coil 3040.

In this case, all of the first to fourth coils 3060, 3070, 3080 and 3090may be inductor coils or transformer coils. Otherwise, the first andthird coils 3060 and 3080 may be inductor coils and the second andfourth coils 3070 and 3090 may be transformer coils.

That is, in the couple inductor, the couple transformer and the coupleinductor-transformer shown in the drawing, the magnetic cores arearranged in two directions (left and right directions about the centralmagnetic path) and coils are wound around the magnetic cores having theabove configuration.

Otherwise, the magnetic cores may be arranged in the front and reardirections in addition to the left and right directions about thecentral magnetic path, so the embodiment can be applied to the4-interleaved boost converter or 4-interleaved flyback converter wherethe cores are arranged in four directions and the coils are wound aroundthe cores.

If the magnetic cores are arranged in four directions, the fifthmagnetic core 3050 corresponding to the central magnetic path may havegreat loss because the fifth magnetic core 3050 has high magnetic fluxvariation. For this reason, the fifth magnetic core 3050 must have sizetwice larger than the other core.

Meanwhile, if the fifth magnetic core 3050 has the property of lowpermeability, the saturation magnetic flux density is high, so the fifthmagnetic core 3050 having the sectional area of the magnetic path thesame as that of the cores located at both sides of the fifth magneticcore 3050 can be employed. In detail, if the fifth magnetic core 3050has the property of low permeability, the magnetic flux variation is lowand the constant magnetic flux is achieved, so the core loss is reducedand the fringing flux is distributed due to the distribution of the airgaps, thereby minimizing copper loss caused by eddy current.

FIG. 31 is view showing an experimental result obtained by the coupleinductor manufactured according to the embodiment.

The experiment was performed by using a control board capable ofcontrolling an operation according to the control operation waveform andone couple inductor according to the embodiment under the conditions of400 W of load, and 90 VAC and 220 VAC of commercial input voltage.Current waveforms Is1 and Is2, terminal voltage waveforms Vs1 and Vs2,input voltage Vac and current waveforms are shown in FIG. 31.

When taking the experimental result into consideration, the coupleinductor according to the embodiment is applicable.

Although embodiments have been described with reference to a number ofillustrative embodiments thereof, it should be understood that numerousother modifications and embodiments can be devised by those skilled inthe art that will fall within the spirit and scope of the principles ofthis disclosure. More particularly, various variations and modificationsare possible in the component parts and/or arrangements of the subjectcombination arrangement within the scope of the disclosure, the drawingsand the appended claims. In addition to variations and modifications inthe component parts and/or arrangements, alternative uses will also beapparent to those skilled in the art.

1. A power supply apparatus comprising: a first magnetic core; a secondmagnetic core having a shape equal to a shape of the first magneticcore; a third magnetic core between the first and second magnetic cores;a first coil wound around one of the first and third magnetic cores; anda second coil wound around one of the second and third magnetic cores.2. The power supply apparatus of claim 1, wherein each of the first andsecond magnetic cores comprises: a first core part; a second core partextending from one end of the first core part vertically to a lengthdirection of the first core part; and a third core part extending froman opposite end of the first core part vertically to the lengthdirection of the first core part, and wherein the third magnetic core isparallel to the first core parts of the first and second magnetic cores.3. The power supply apparatus of claim 2, wherein the first magneticcore has a shape of ‘U’, the second magnetic core is symmetrical to thefirst magnetic core about the third magnetic core, and the thirdmagnetic core has a shape of ‘|’.
 4. The power supply apparatus of claim2, wherein the first and third magnetic cores are spaced apart from eachother by a first air gap formed between at least one of the second andthird core parts of the first magnetic core and the third magnetic core,and the second and third magnetic cores are spaced apart from each otherby a second air gap formed between at least one of the second and thirdcore parts of the second magnetic core and the third magnetic core. 5.The power supply apparatus of claim 4, wherein the first air gap isformed in at least one of right sides of the second and third core partsof the first magnetic core and a left side of the third magnetic core,and the second air gap is formed in at least one of left sides of thesecond and third core parts of the second magnetic core and a right sideof the third magnetic core.
 6. The power supply apparatus of claim 2,wherein the first coil is wound around one of the first to third coreparts of the first magnetic core, and the second coil is wound aroundone of core parts of the second magnetic core, which is symmetrical tothe core part of the first magnetic core around which the first coil iswound.
 7. The power supply apparatus of claim 6, wherein the first coilis wound lengthwise along the first core part of the first magnetic coreor wound in a direction crossing a length direction of the first corepart of the first magnetic core, and the second coil is wound lengthwisealong the first core part of the second magnetic core or wound in adirection crossing a length direction of the first core part of thesecond magnetic core.
 8. The power supply apparatus of claim 7, whereinthe first coil includes a plurality of first coils disposed on aplurality of regions, respectively, while being connected with eachother in series, and the second coil includes a plurality of secondcoils disposed on a plurality of regions, respectively, while beingconnected with each other in series.
 9. The power supply apparatus ofclaim 1, wherein the third magnetic core comprises: a fourth core part;a fifth core part vertically extending from one end of the fourth corepart in a left direction; a sixth core part vertically extending fromone end of the fourth core part in a right direction; a seventh corepart vertically extending from an opposite end of the fourth core partin a left direction; and an eighth core part vertically extending fromthe opposite end of the fourth core part in a right direction, and thefirst and second magnetic cores are parallel to the fourth core part ofthe third magnetic core.
 10. The power supply apparatus of claim 9,wherein the first and second magnetic cores have a shape of ‘|’, and thethird magnetic core has a shape of ‘H’.
 11. The power supply apparatusof claim 9, wherein the first coil is wound lengthwise along the firstmagnetic core or wound in a direction crossing a length direction of thefirst magnetic core, and the second coil is wound lengthwise along thesecond magnetic core or wound in a direction crossing a length directionof the second magnetic core.
 12. The power supply apparatus of claim 9,wherein the first coil is wound around one of the fifth and sixth coreparts, and the second coil is wound around one of sixth and eighth coreparts, which is symmetrical to the core part around which the first coilis wound.
 13. The power supply apparatus of claim 12, wherein the firstcoil includes a plurality of first coils disposed on a plurality ofregions, respectively, while being connected with each other in series,and the second coil includes a plurality of second coils disposed on aplurality of regions, respectively, while being connected with eachother in series.
 14. The power supply apparatus of claim 9, wherein thefirst and third magnetic cores are spaced apart from each other by athird air gap formed in at least one of between the first magnetic coreand the fifth core part and between the first magnetic core and theseventh core part, and the second and third magnetic cores are spacedapart from each other by a fourth air gap formed in at least one ofbetween the second magnetic core and the sixth core part and between thesecond magnetic core and the eighth core part.
 15. The power supplyapparatus of claim 14, wherein the third air gap is formed in at leastone of between a right side of the first magnetic core and a left sideof the fifth core part and between the right side of the first magneticcore and a left side of the seventh core part, and the fourth air gap isformed in at least one of between a left side of the second magneticcore and a right side of the sixth core part and between the left sideof the second magnetic core and the right side of the eighth core part.16. The power supply apparatus of claim 14, wherein the third air gap isformed in at least one of between a top surface of the first magneticcore and a bottom surface of the fifth core part and between a bottomsurface of the first magnetic core and a top surface of the seventh corepart, and the fourth air gap is formed in at least one of between a topsurface of the second magnetic core and a bottom surface of the sixthcore part and between a bottom surface of the second magnetic core and atop surface of the eighth core part.
 17. The power supply apparatus ofclaim 1, wherein the first and second magnetic cores have highpermeability, and the third magnetic core has low permeability.
 18. Thepower supply apparatus of claim 1, wherein the first and second magneticcores have low permeability, and the third magnetic core has highpermeability.
 19. The power supply apparatus of claim 1, furthercomprising: a fourth magnetic core; a fifth magnetic core; a third coilwound around the fourth magnetic core; and a fourth coil wound aroundthe fifth magnetic core, wherein the first magnetic core is formed in afirst direction about the third magnetic core, the second magnetic coreis formed in a second direction about the third magnetic core, thefourth magnetic core is formed in a third direction about the thirdmagnetic core, and the fifth magnetic core is formed in a fourthdirection about the third magnetic core.
 20. The power supply apparatusof claim 19, wherein the first, second, fourth, and fifth cores have across shape about the third magnetic core.
 21. The power supplyapparatus of claim 1, wherein the first and second coils are inductorcoils, and the power supply apparatus includes a couple inductor. 22.The power supply apparatus of claim 1, wherein the first coil is a firsttransformer coil including a primary coil and a secondary coil, thesecond coil is a second transformer coil including a primary coil and asecondary coil, and the power supply apparatus includes a coupletransformer.
 23. The power supply apparatus of claim 1, wherein thefirst coil is an inductor coil, the second coil is a transformer coilincluding a primary coil and a secondary coil, and the power supplyapparatus includes a couple inductor-transformer.